A Low-Voltage SiGe BiCMOS 77-GHz Automotive Radar Chipset

NICOLSON et al.: LOW-VOLTAGE SiGe BiCMOS 77-GHz AUTOMOTIVE RADAR CHIPSET 1097
Fig. 15. Die photograph of the receiver (LNA, VCO, mixer, and IF amplifier).
(515 "m2 460 "m).
Fig. 16. 77-GHz PA layout with pads (390 "m2 280 "m).
Fig. 17. Miller divider die photograph (250 "m2 180 "m).
HBT varactors [7]. Also provided in the SiGe BiCMOS process
is a thick-metal BEOL.
A die photograph of the receiver, including the LNA, VCO,
and mixer with on-chip balun and IF amplifier, is shown in
Fig. 15. A die photograph of the 77-GHz PA is shown in
Fig. 16, and a die photograph of the Miller divider is illustrated
in Fig. 17. The die areas are indicated in the figure captions,
and are small in comparison to other circuits reported in the
Fig. 18. Simulated and measured LNA ƒ-parameters at 1.8-V/2.5-V and
1.5-V/1.8-V supply.
Fig. 19. Measured LNA ƒ-parameters over temperature.
literature because lumped inductors are used in place of transmission
lines.
V. SIMULATION AND MEASUREMENT RESULTS
A. LNA
The LNA power gain ( ) is shown in Fig. 18, measured
at 1.8-V/2.5-V and 1.5-V/1.8-V supplies. The LNA achieves
25-dB peak power gain at 86 GHz with a 3-dB bandwidth of
7 GHz, and is operable down to 1.5-V/1.8-V supply with only
2-dB gain reduction. The input return loss, less than 15 dB
from 80 to 94 GHz, is shown on the same plot for different bias
current densities of the input transistor . The LNA gain was
also measured over temperature, as illustrated in Fig. 19, and
maintains 20-dB gain even at 125 C.
B. PA
The PA -parameters were measured from 57 to 94 GHz over
temperature and are illustrated in Fig. 20. The input return loss
is less than 15 dB from 70 to 90 GHz. In Fig. 21, measurements
at 77 GHz show the PA achieves small-signal of